Method of fingerprinting



Patented Mar. 18, 1941 burrs!) STATES METHOD OF FINGERPRINTING William Heinecke, West Orange, N. J asslgnor to Graphic Arts Research Corporation, Verona,

No Drawing. Application October 3, 1939, Serial No. 297,662

Claims.

This invention relates to new and improved methods of fingerprinting, designed to allow the rapid taking of fingerprint impressions from a person, upon plain untreated papers, without the 5 usual objectionable usage of printers ink, and also designed to permit the employ, if desired, of non-toxic chemicals. The invention primarily involves the application of chemical principles to the present inconvenient method of making fingerprints, although my invention also includes certain mechanical methods for the making of fingerprints which avoid the application of objectionable substances to the fingers of the person fingerprinted.

Heretofore, the most common method of making fingerprints was to apply printers ink upon the fingers of the subject, and then directly impress the inked fingers upon paper, This method is objectionable, because the subject's fingers will be badly stained, with the result that universal fingerprinting, for means of identification, has met with opposition. Also, under applicants Patent No. 2,082,735, there has been in use, to a moderate degree, the method of impregnating special papers with chemicals, which paper may have fingerprints developed thereon, by impressions made from the finger tips of the subject,

by virtue of re-agent chemicals being applied from the fingerprints to the specially prepared paper by impressional contact. However, the impregnated paper method has been found to be too expensive for wide use, although the same has been employed in certain banks and hospitals. Also,

there is suggested in Patent No. 1,700,262, granted 35 to the present applicant, Dr. William Heinecke,

the use of certain photographic methods for making fingerprints.

Therefore, it is an object of my invention to provide a simple economical method of taking fingerprints, upon plain untreated papers, by the application of chemical principles without the necessity of using staining substances and preferably by the employ of non-toxic compositions. It is a further object of my invention to provide a simple chemical re-agent, which is stainless, which can be applied to the finger tips for impressional contact upon untreated papers, the impressions of which may be developed simply by the use of heat, or light, or heat and light in conjunction, or in certain instances, merely by oxidation. This method will hereinafter be identified as the single re-agent method.

It is a further object of my invention to employ a non-staining chemical re-agent for application L as to the subjects finger tips, thus causing a fingerprint impression on plain paper by impressional contact, the impressions of which may be developed into clear fingerprints by the application of a second chemical composition: the application of the second chemical composition may be accomplished by the use of the same in a colorless spray form, or acolorless powder, or by wet pads or volatile vapors. This method will be referred to hereinafter as the two re-agent method.

It is a further object of my invention to provide a simple mechanical method of making fingerprints which involves the application of a thermoplastic material to the finger tips of the subject to make an impression upon plain untreated paper, with subsequent dusting of the thermoplastic impression formed thereby with a colored powdered material, such as powdered asphalt, by dusting, and then fixing the fingerprints formed thereby by heat.

It is also a further object of my invention to provide in a suitable cake or paste, or ink pad, or liquid'form, the above mentioned chemical reagents so that they may be conveniently utilized by the subjects to be fingerprinted, and it is further my intent, for purposes of economy to utilize plain untreated paper.

It is a further object of my invention to produce fingerprints by my method which are brownish or black (namely non-actinic colors) so that the same may be photographed.

Also, it is my purpose to permit the making of fingerprint impressions particularly bythe use of non-toxic, non-staining chemical substances, with the view that the economies and conveniences of such methods will eliminate the present prejudices to universal fingerprinting, with the attendant manifest advantages.

In my method, identified above as the "single re-agent method, I utilize plain untreated paper and develop after impressional contact, as indicated above, by heat or light, or heat and light together, or merely by oxidation.

For the purposes of illustration only, I will now describe certain examples of the single re-agent method:

Example 1 By weight, one part of alloxanthine and parts of oxalic acid, together with 50 parts of glycerin as a vehicle may be used as a colorless non-toxic 1 chemical inking substance for the giving of impressional contact finger prints upon plain untreated paper, and may be developed by the application of a moderate degree of heat alone, temperatures in the neighborhood of about 250 degrees F, being suflicient. If desired, a V; part of indoline may be substituted for the alloxanthine above.

Example 2 By weight, two parts of stannous chloride and one part of sodium thiosulphate, together with about 50 parts of glycerin and one part of water, as a binder, will serve to make impressional finger prints upon plain untreated paper under conditions as indicated in Example 1.

Example 3 By weight, one part of resorcin and one part of sodium nitrate in about 30 parts of glycerin will develop by heat.

Example 4 One part of formaldehyde and one part of cinnamlc acid and about 30 parts of glycerin will develop by heat.

Example 5 All soluble nitrates, for example, one part of bismuth nitrate in a colloidal vehicle comprising one part gum arabic, one part water and one part glycerin may be developed by heat.

Example 6 One part silver phosphate dissolved in a solution comprising one part citric acid, 10 parts glycerin, 2 parts oleic acid will make contact impressions which may be developed by light.

Example 7 One part silver stearate, 20 parts glycerin, 10 parts alcohol may be utilized to make impressional contacts developable by light, or heat, or both' jointly.

Example 8 Two parts bismuth nitrate,- two parts sodium thiosulfate, 40 parts glycerin and 10 parts water may be developed by heat.

Example 9 Five parts nickel nitrate, 50 parts glycerin and four parts of potassium sulfocarbonate may be developed by heat.

Example 10 One part of silver fluoride, together with a vehicle comprised of '75 parts castor oil and parts of glycerin, will serve as a chemical inking means to give fingerprint impressions which may be developed by the use of light alone.

Example 11 Ten parts of silver chloride may be substituted for the silver fluoride in Example 10, if desired, with like results.

Example 12 The formula given in Example 10 may be developed by heat and light together.

Example 13 Although slightly toxic, one part of potassium silver cyanide (KAgCn2) in 50 parts of glycerin in another binder may be developed by heat and light jointly.

Examples of my so called two re-agent method for making fingerprints are as follows:

Example 14 Although toxic, any copper, bismuth or iron salt reacted with sodium dlethyl-dithiocarbamate (the latter in a 5% water or alcohol solution may be utilized: more specifically, one part of copper nitrate in 40 parts water or alcohol, plus a vehicle of about 40 parts of gum arable, may be utilized in pad form, and developed by the application of the said sodium diethyl-dithiocarbamate solution applied in spray form or by a pad, or in any convenient manner. Alternatively, the sodium diethyl-dithiocarbamate may be applied in powder form, while the copper nitrate impressions are moist, particularly conveniently after sodium diethyl-dithlocarbamate is combined with starch powder.

Example 15 By weight, one part of para-amidophenetol in 10 parts of water, plus a vehicle of about 11 parts of gum arable, may be utilized for making the impressional finger print impressions by contact upon plain untreated paper, and such impressions may be developed by utilizing a 10% chloryl hydrate solution in water or alcohol.

Example 16 By weight, 20 parts of furfurol hydrochloride and 30 parts of glycerin solution may be used in Example 15 and the impressions developed by the use of a saturated solution of urea in a 10% alcohol and water solution. If desired, the urea could be used in powdered form to develop such impressions while the impressions are wet.

Example 17 A 5-10% solution of para nltrosodimethylanoline in glycerin may be utilized from a pad to make contact impressions and may be developed by means of a chemical reagent in powder form such as beta naphthol or gallic acid.

Example 18 One part of furfurol alcohol in a vehicle comprised of one part of di-ethyline glycol, or polymers thereof, may be developed by contact with any mineral acid.

Example 19 One part of cinchoine sulphate in five parts of glycerin may be developed by contact with a saturated alcoholic solution comprised of parts potassium iodide and 1 part iodine.

Example 20 Five parts of citrophen in 50 parts of glycerin may be developed by a 10% sodium carbonate aqueous solution or sodium carbonate in powdered form. I

A third manner of conveniently making fingerprints is my so called mechanical method. In this method, waxy heat thermoplastic material may be utilized in cake or paste form applied by the impressional contact method to plain untreated paper and then dusted with appropriate powders, as may be evident in the following examples:

Example 21 phaltum or nigrosine powder adhering in definite fingerprint lines to the paper.

Example 22 One part of ethanolamine, one part rosin and one part shellac may be utilized to make impressional contacts upon plain untreated paper and then dusted with dihydroxyanthrachinone.

The methods explained above are new andunique and once understood, may be the subject of various variations, particularly by substitution of the various chemical compositions suggested. The chemicals involved may be utilized in cake form, paste, pads, etc., and produce nonactinic colors. It will be observed that with the exception of the example involving copper salts, that the substances are all non-toxic and are stainless.

In the event that the chemical compositions used for making the impressional contact are colorless, a small amount of an appropriate nonstaining substance, such as one of the alizarin dies, may be added to the chemical compositions, in order that it may be observed as to Whether the contact impressions of such are perfect, prior to the development thereof. In this connection, it is obvious that the non-staining substance used must be compatible with the chemical composition used for making the impressions.

Accordingly, the examples given are not to be deemed as limiting the invention; for the scope thereof reference should be had to the appended claims.

1. The method of producing finger prints upon plain untreated papers which includes applying contact impressions of the fingers to the paper by means of substantially non-staining chemical compositions which are inert to the paper and to the epidermis of the human body and developing the chemical compositions of said impressions solely by heat.

2. The method of producing finger prints upon plain untreated papers which includes applying contact impressions of the fingers to the paper by means of substantially non-staining chemical compositions and developing the impressions solely by light.

3. The method of producing finger prints upon plain untreated papers which includes applying contact impressions of the fingers to the pa- I per by means of substantially non-staining chemical compositions and developing the impressions by light and heat jointly.

4. The method of producing finger prints upon plain untreated papers which includes applying contact impressions of the fingers to the paper by means of substantially non-staining YWILLIAMHEINECKB. 

